When you spawn an object it gets placed on the default location Vector3(0,0,0). You have to tell the spawned object to be positioned at a certain location.
the first time you load a model, there might be a delay. However the second time you spawn a model, you can use Copy() function. This uses the existing model as a reference. http://www.leadwerks.com/werkspace/page/documentation/_/command-reference/asset/assetcopy-r40
How is your spawning set up? If you are just loading a model then the reason why you have that error is because the loaded model doesn't have script attached. Save your enemy with the script attached as a prefab and load that instead of the model.